Inspection Procedure

WARNING: This page is about a different car, the 2002 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.

Check Voltage Between Terminals TAM And SG-1 Of Integration Control And Panel
Preparation:

Remove integration control and panel with connectors still connected.

Check:
1. Turn ignition switch to ON.
2. Measure voltage between terminals TAM and SG-1 of integration control and panel connector at each temperature.
OK:

Voltage:

at 25°C (77°F): 1.35 - 1.75 V

at 40°C (104°F): 0.85 - 1.25 V

Fig 1: Locating TAM & SG-1 Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: Go to step 2.
2. OK: Proceed to next circuit inspection shown on problem symptoms table. See PROBLEM SYMPTOMS TABLE . However, if DTC 12 is displayed, check and replace integration control and panel.

NOTE: When installing the ambient temperature sensor, be sure to connect the sensor connector before connecting the battery.

As the temperature increases, the resistance decreases.

Fig 2: Locating Ambient Temperature Sensor Terminals

Check Ambient Temperature Sensor
Preparation:

Disconnect ambient temperature sensor connector.

Check:

Measure resistance between terminals 1 and 2 of ambient temperature sensor connector at each temperature.

OK:

Resistance:

at 25°C (77°F): 1.6 - 1.8 kΩ

at 50°C (122°F): 0.5 - 0.7 kΩ
1. NG: Replace ambient temperature sensor.
2. OK: Go to next step.
Check Harness And Connector Between Ambient Temperature Sensor And Integration Control And Panel
1. NG: Repair or replace harness or connector.
2. OK: Check and replace and integration control and panel.